Production of condensation products from aromatic hydrocarbons



c tion of condensation productsfrom aromatichy- Patented Apr. 9, 1935 Otto Drossbach and" Ernst Roe ll; 'Luawigshare i on-the-Rhine; Germany; assignors to I. 1}. Farbenindustrie; Aktiengesellschaft; FrankiortT-eo ,Nb brawing; V "1930, Serial The present applicationt has-been' divided out from 'ourrcopending applicationiser, No.-fl=99,9d7,;

filed December 4th, l930. r The present} invention relates to: the producment ofiaromatichydrocarbons suchas benzene,-

toluene, xylene; naphthalene" or anthracenep at temperatures Lot 700 C, and more. Innorder-to' V obtain a: betterlutilization of the heated chamber it has beenproposed to allow thevapors of:-the

hydrocarbons, if desired in mixture with steam,

.to flowrover .piecesofpquartzypumice oracokez Working in. this manneris, not suitable for the preparationeof -."uniform:'products, asior exame plejgof 'diphen'ylirom; benzene, because aalarge number of other substances, in-particular highercondensation products, are formed :and a part of I theginitial materialsis entirely: destroyed" by the 1 formation of methane. andthe deposition of cars drawback may be obviatedrbycarrybon. \This which'diphenylis mainly formedJout in this case only extremely small yields, are obtained. I

- We havenow. found th tigoodyields Iof-the desired condensation Vproductssin' particular of diphenyl' frombenzene are obtained without any appreciable ,formation of higher-condensation roducts bys ca ym o t c ndens t on; aromatic hydrocarbons containing ,less; than 2 carbon atoms inan aliphatic side chain if;such be present, in the presence of catalysts of diilicultlyv reducible, preferably difiicultly fusible, metal oxides. Hydrocarbons containing more than 1 carbon atom inan aliphatic side chain cannot be employed, since otherwise styrene and its homologues would be formed, As examples of suitable catalysts may be mentioned. in particular difiicultly reducible metal oxides, as for, example the oxides of the earthlmetals, i; e. the alkaline earth or earth metalssuch as calcium, barium, strontium, magnesium, titanium, cerium, zirconium, thorium, or of'tungsten, molybdenum, man-v ganese, chromium uranium, aluminium; vanadium, beryllium and the like'but also, oxides of alkali metals or mixtures thereof with theaforesaid oxides may be employed. Instead of feeding the reaction space with the said oxides, compounds of the corresponding metals may be used which are decomposed into oxides by heating. The catalysts are preferably subjected toa pretreatment with aliphatic'for other easily decomposed hydrocarbons, such as ethylene or benzine' r. r 74f class, (ct sec-nee 3 1,

' conjunction with 'pij'eponderating difficultlyredu'cible metalfoxides.

V temperatures {are "generally ingout theprocess atthe lowest: temperature at in'gon the"'catalystfor too long aperiodiof t' e 1) Eur hydrocarbons, at temperatures of about 700C-., so that theyjareprovided wit stabilized thereby. In the aforesaid compounds of the metals, the oxides-of which are'referred' to above, the metals'mayconstitutethe anions as well as thecations, as for example ,vanadates,

chromatesf tungstate molybdates, ialun'iinates,

zincates, ne: calciufm' omaluminium":borates J a phosphatesior isilicates' andcompounds containe ing metals anions and] cations such' as calcium,

metal"oxides,- o' othencompOundsof thecorfef PRoDUc'rioN 0F @ONDENSATION arson AROMATICH; nrnnoozm bariun i', c"rium-or zinc chromates; cerium tungg; stateor molybdate andthe'like. Easilyredu'cible" usasmeethe tendtp produce adecomposition of the miner hydrocarbons; and rormamen' ef a shot or i amorphousfcarboni Cobalt oxide; how ever, which is ilesseasily reducible" than lead oxide," may be employed small quantities. in

iIt' is preferable to select the' -velocityof V the'hydrocarbonvaporssufl'iciently high thatonly I t from about 10 to '15 per cent-oi't helatter "are con:- verted'into compounds of the type of dip )quantities" or The reaction) bet-wee about 5cm henyl in' J a sing-1e 'iopera'tiom unconverted vapors f lyst; "theypiev'ent the hydrocarbons from remain} j and also preventthe iormation of -higher "con I ably employedin a dilutedstate. The jdilution' of the hydrocarbons to -be converted can be efiected by the addition of inert gaseous diluents such as gasesor vapors inert to theinitial mate?- rials as ,for example nitrogen, methane, water; vapor or carbon dioxide, whereas oxygen'or gases 3 containing the same cannot be employed asdil-L silver are not employed even whenwater vapor j is employed asa diluent.

" The process maybecarned out in a cycleQand" materials to the reaction chambera very good it t t by repeatedly returningthe unconverted initial and time'is obtained. U

yield,.up to quantitatiye yields, per unit of space The ,iollowingexarnples wni mrther; illustrate not restricted to'theseexa'mples.

' Eit'ample 1 the nature ofthis invention, 'bu t the inventionjs -A catalyst is prepared bygraphitizing'rnoulded .magnesium oxide-with ethylenejat' 700 C; 'Vawporized benzene is then led at 775 C. Over the cat- I alys't in an amcunt jper -houriicalculatedEwith; reference to theunitper yolumeof the benzene inthe liqu'id'st'ate) correspondirigltoLS times the volume .of thecatalyst employed; 'The vaporsleaving the reaction vessel are cooled; to the" boiling pointof benzehewherebyi the-diphenylforined 1 is separated? The unconverted; benzene is ;re,-

turned tothe reaction-yesselafter replenishing.

the benzene whichhas been used up. Atlast 10 per cent of the benzene'is converted i'na single f operation and aftenreturning the residual ,bem

zen'e about: 90 per-cent, or. th ben ene mp oyed is converted into .dipheny1 and about--10 percent is ,conyerted'. into. higher; condensation products," mainlyiintodiphenyl-benzene 7 mane-z A mixture'of l-part by -yol ume' 1 of naphthalene 'vapo'rand 0.2 part by .volumejpf water vapor passed at 800 pkweha eatalystg which hasbeen prepared by graphitizingiamixture of equalparts ottunestic acid and eofraluni i m Qxide.-by:paS ing vapors .of; benzine thereoveret 'wm ,(l the velocity of the initial vaporousmixtureper hour andperrliter' of the catalyst being one-liter oi the. v naphthalene, andiwatermixturecalculated in the 1 liquid form. The .1 vapors, issuing; from. the reac- I naphthalene areremcyed, which are, then, pressed and returned into-the process. The distillation tion Vessel 'areacooled and thefrea ction product together with unaltered naphthalene is separated from the waterl v'lfh rsol reacti nim d zcta a subjectedto a distilleiiiqniatf l5qfQ with super heated steam whereby the}. main? quantities of sidueg con ti ut fig; a tou h. brownzmass s: the subjected mii actionalnistillatiqa At a frornZlS i to i 2209 C remainders of naphthalene crystallizes out on cooling. After evaporating thexylene a tough, brown mass remains from "'phalt like mass.

diluent inert to the initial whichf'urther crystals separate out after prolonged standing which consistof a, a' diimphthyl having a melting'point of 156 C.; the residue con-' T tains higher'condensation products of naphthalene. The residue ofthe distillation is an as- In one "operation about 20 per cent of the naphthalene are brought to reaction, two thirds of thexreaetionzproduct consisting of 'dinaphthyl and mainly. of 5; 1,8 -dinaphthyl.

What we clairnis;+- V j "1; 'In the catalytic production of condensation products oi aromatic monoand binuclear hydro carbons, in which any aliphatic side chains pres exit contain less, than two carbon atoms, while heatingltoirom 500". to 800 0., the step "which one diflicultly reduciblew metalloxide and, a.superfieialcoating. of lustrous carbombut'inthg-absence offreeoxygenf v 2.1 In the -.catalytic of condensation products'of-aromaticmonoand binuclear hydro carbons, in which any. aliphatic side chains prwq 7 ant contain less than two carbon-.atoms, while heating to-from 500 to 80D? C. ,"13he step which comprises carrying out. the reaction in the pres- 'enceof a catalyst comprising essentially at least 20 comprises carrying outthe. reaction in the presence of acatalyst, comprising essentially at least one dimcultlyreducible metal oxide andf a superhydrocarbon.

'ficial coating of I lustrons carbon; an'd of a gaseous (T 3;. In. the catalytic 1 prodnction of condensation products of aromatic mono and 'binuclear hydrocarbons, in whichany'aliphatic. sidechains pres--' fenta contain less than .twobarbori: atoms; while heating to froni 500 to800 l.C.,'-:t he step which comprises carrying :out the 1'eeetion in thepres ence of a catalyst comprising essentially at one difiicultly :r'eduhible metaloxide anda super ficial coating oj lustrous carbon; but in the ab- 'sence of free-oxygen, while passing. the initial hydrocarbon over the catalyst at such a 'high Velocity thatup t0 15 -per cent onlyof the hydro carbonis condensed in one operation. 4.=In th'ejcatalytic production of; diphe'nyl irom benzene, whi1e=heatingto from .790 to 800 C.',

the step whichcomprise's carryingoutthe reaetion in the'lpresence ofa catalystcomprising essentiallya-at-least one cliflicultly reducible metal,

oxidef'anda superiieialcoating of lustrous carbon, 

